1. Field of Invention
This invention relates to a method of making an automatically dismountable roll paper product formed from an elongated sheet of paper wound about a core. During winding, the core and paper are relatively displaced axially to provide a groove at one end of the roll product and a boss at the other.
2. Description of the Prior Art
U.S. Pat. No. 3,038,598 issued June 12, 1962 to Layton et al., relates to an automatically dismountable roll of strip material which has a bearing wall adapted to be supported upon an appropriate supporting member in a dispenser cabinet and to be automatically dismounted therefrom when it has been consumed to a predetermined extent. U.S. Pat. No. 3,089,659 issued May 14, 1963 to J. L. Perrin discloses the method of automatically dismounting the roll product of U.S. Pat. No. 3,038,598. The bearing wall is formed by the convolutions of the roll product which are relatively disposed to form a recess or detent in the end of the roll. U.S. Pat. No. 3,282,525 issued Nov. 1, 1966 to H. W. Rehr illustrates an apparatus and method which have been utilized to form the recess and bearing surface. According to this latter patent laterally movable score slitting knives are employed in combination with a platen roll to cut a parent web into a plurality of web strips which are wound on a revolving winder that is fixed in the cross machine direction. The apparatus of the aforesaid Rehr patent is restricted to the use of score slitting knives which limits its applicability to certain types of web materials and results in a relatively high knife blade wear rate. Further, the requirement for synchronized knife motion requires a rather complex and expensive knife support and transport mechanism.
Another method that has been employed to form the recess is to actually bore the recess at the end of the roll after it is formed by means of a rotating cutting tool. This approach has the drawback of producing waste. In addition, if the cutting tool is not maintained in a sharp condition or the roll is soft or embossed the portion of the roll product forming the recess may become rough and ragged and not aesthetically pleasing to the end user.